Comparing the Impact of Metoclopramide versus Ondansetron on Pain Reduction Caused by Etomidate Injection in Patients under General Anesthesia.

Abstract

Background: Etomidate is a short-acting intravenous anesthetic commonly used for induction of general anesthesia and sedation. Preventing pain caused by etomidate injection can improve patient comfort and broaden its clinical use. This study compared the effects of metoclopramide and ondansetron on etomidate injection-related pain in patients undergoing general anesthesia.

Materials and methods: In this randomized clinical trial conducted at Al-Zahra Hospital, Isfahan, from 2021 to 2022, 90 patients were randomly assigned to three groups (n = 30 each): metoclopramide (Group A), ondansetron (Group B), and normal saline (Group C, control). After drug administration, 0.3 mg etomidate was injected, followed by 1 mL of 2% lidocaine. Pain intensity during etomidate injection was recorded. Hemodynamic parameters-including blood pressure, heart rate, and arterial oxygen saturation (SaO₂)-were measured at 5, 10, 15, 30, 45, and 60 minutes, and upon discharge from recovery. Duration of surgery and recovery were also documented.

Results: The control group exhibited a higher mean pain score than the intervention groups. Pain intensity differed significantly between the metoclopramide and control groups (P = 0.001), but not between ondansetron and control (P = 0.762) or between metoclopramide and ondansetron (P = 0.675). Both metoclopramide and ondansetron effectively reduced etomidate injection pain without significant differences in hemodynamic stability or recovery duration.

Conclusion: Both metoclopramide and ondansetron attenuate pain associated with etomidate injection during induction of general anesthesia, with no clear superiority of one drug over the other. Their comparable efficacy supports either as an appropriate option for preventing etomidate-related pain.